"The suspects were arrested on a vessel MT Ashkay which was intercepted by a naval ship NNS Predator off Sangana River with cargo suspected to be stolen crude oil," Mr Olutoyin said.

"The product on board MT Ashkay is suspected to be stolen crude of about 157,822 litres. They didn't have papers to justify the cargo," he said adding the tanker does not have the Nigerian Port Authority's Bunkering Permit, nor the Joint Task Force, Operation Pulo Shield certificate of registration.

Speaking to PTI, on the sidelines of an African Union summit holding in Addis Ababa in Ethiopia, Nigeria's Foreign Minister Olugbenga Ashiru said he is appealing to foreign countries to enlighten their citizens on the dangers of illegal oil bunkering in Nigeria.

"Most of the ships arrested for crude oil bunkering in the past belonged to foreigners. If there is no willing foreign buyer, there won't be a seller," Mr Ashiru said adding that any foreigner caught for bunkering would automatically face the Nigerian court process.